1 . Field of the Invention
The present invention is generally related to a current sensor and, more particularly, to a current sensor which comprises a housing that is formed to provide a planar member that can be captured between an electrical conductor which serves as a primary winding of the current sensor and an external object on which the current sensor is to be mounted.
2. Description of the Prior Art
Many different types of current sensors are well known to those skilled in the art. The current sensors can comprise magnetically sensitive components, such as Hall effect devices, and magnetically permeable core members or, alternatively, the current sensors can comprise a current transformer with a toroidal secondary winding disposed within a housing and shaped to receive a primary winding through a centrally located opening thereof.
Regardless of the particular construction and operation of the current sensor, most current sensors require some means to attach the housing to an external object. In most known applications of this type, the housing of the current sensor is molded to form feet or tabs extending therefrom and holes are formed in the feet or tabs to permit screws, bolts or rivets to attach the housing to an external object. Alternatively, holes are formed through a portion of the housing itself for the same purposes.
U.S. Pat. 5,180,970, which issued to Ross on Jan. 19, 1993, describes a mechanically adjustable current sensor and a method for making the same. The current sensor is provided with a flux concentrator which is made of two or more annular laminae. Each lamina plate is provided with a gap that is formed in its circumferential length. Each lamina plate has a gap which is defined by two opposing faces. The laminae are stacked with their planar surfaces in contact and in such a way so as to define a central opening. The gaps of the laminae are arranged proximate each other. One lamina plate is rotated relative to another in order to change the width of the effective gap by misaligning the faces of one gap relative to another. The lamina plate is rotated during the manufacture of the current sensor while an output voltage signal is measured as a function of the current passing through an opening of the flux concentrator. The degree of rotation of the laminae plate is determined as a function of the output signal in order to achieve a preselected current/voltage relationship. By achieving a consistent relationship between current sensors made in accordance with the present invention, interchangeability from one current sensor to another can be achieved in a low cost current sensor.
In most applications of current sensors, a primary electrical conductor extends through a central opening of the sensor. Typically, the primary conductor is placed in its position through the opening of the sensor after the sensor is attached to the external object, such as a printed circuit board (PCB). Therefore, the manufacture of a device using a current sensor usually requires two separate operations to be performed. First, a plurality of screws, bolts or rivets are associated with holes formed in the housing, or tabs attached to the housing, and the current sensor is attached to the external object. After this attachment process is complete, a primary electrical conductor is associated with the sensor and extended through its central opening.
It would therefore be beneficial if the manufacturing and assembly operation of a device which uses a current sensor could be minimized by removing the necessity of the dual operations of attaching the sensor to an external object and then arranging a primary electrical conductor through the opening of the current sensor.